Roger Federer opened up his ATP World Tour Finals in memorable fashion as he eased past number six seed Tomas Berdych with a 6-4 6-2 victory at the O2 Arena this evening.

Things did not start in the best of circumstances for Federer, who was broken in the second game of the first set, as Berdych made use of some tame second service to break point and move into a 2-0 lead.

Back came Federer soon enough, however, leaving the Swiss to take two games in a row with a strong break of his own in order to leave things tied at 2-2 to sum up an intriguing beginning to proceedings.

Both players remained intensely focused despite a few wayward efforts leading up to 4-4, where Federer was able to seize the initiative when Berdych produced three unforced errors to give away another break and move things to 5-4.

That point allowed Federer to serve for the first set, which he completed with relative ease following two standout aces and another unforced error from his opponent.

Things soon became even worse for a struggling Berdych, who succumbed to some masterful defensive work from Federer, who broke twice in a row at the first point of asking in the second set, allowing the Swiss to go 6-4 4-0 ahead having won seven games straight.

Berdych was able to stop the rot having claimed two games at 5-2, but it was not enough to prevent Federer from sealing a stylish win.